Open AccessUnraveling the Mechanism of Removing NA Contamination by TMAH-Based Cleaning Solution During Post Co-CMP Cleaning
Author(s) -
HaoXiang Cui,
Tengda Ma,
Baimei Tan,
Xiaofeng Sun,
ZiXuan Feng
Publication year - 2022
Publication title -
ecs journal of solid state science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.488
H-Index - 51
eISSN - 2162-8777
pISSN - 2162-8769
DOI - 10.1149/2162-8777/ac5ead
Subject(s) - x ray photoelectron spectroscopy , cleaning agent , materials science , contamination , electrochemistry , chemical engineering , contact angle , nuclear chemistry , chemistry , composite material , ecology , electrode , engineering , biology
Nicotinic acid (NA) has been widely applied to inhibit the corrosion on Co surface in the Co interconnection chemical mechanical polishing (CMP). The insoluble Co(II)-NA complexes can be observed as organic residues on Co surface after CMP. In this work, the effects of different cleaning solution combination between TMAH and three complexing agents (TETA, EDTA and Gly) on removing NA contamination on Co surface were researched. Electrochemistry, contact angle, X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM) were applied to explore the cleaning effect and mechanism. The results showed that the synergetic action of 0.15 wt% EDTA and 0.15 wt% TMAH had the optimal removal effect and could significantly remove NA contamination on Co surface. Besides, the molecular activity of NA was calculated based on Density functional theory (DFT) to clarify the mechanism of cleaning process. The results showed that the bond between NA and Co 2+ was broken and the Co(II)-NA complex film was decomposed under the action of the cleaning solution.